Bow straightening device



1785- 1962 l. M LEOD HILL BOW STRAIGHTENING DEVICE Filed NOV. 30, 1960 III. III-I (am-25 552 n5 uxs. O.

INVENTOR: IAN M LEOD HILL m OE Lu W ATTYS.

United States Patet 3,026,620 BOW STRAIGHTENING DEVICE Ian McLeod Hill, Lurgan, Donacloney, Northern Ireland, assignor of one-half to John Dalgiish & Sons Limited, Thorniiebank, Glasgow, Scotland, a British company Filed Nov. 30, 1969, Ser. No. 72,742 4 Claims. (Cl. 2651.3)

This invention relates to a device for removing backward bow in the weft threads if woven fabrics or in courses of knitted fabrics.

Devices for the purpose aforesaid heretofore have incorporated bent bars and bent rollers and have been relatively complicated in construction and operation.

An object of the present invention is to provide a relatively simple device for the purpose aforesaid.

According to the present invention I provide in or for apparatus including fabric take-off and take-up mechanisms and means for progressing fabric in the direction of its length between said mechanisms, a device for the purpose aforesaid comprising a shaft disposed or adapted to be disposed transversely to the line of progress of the fabric and in such relation to said mechanisms as to effect a return bend in said line of progress, a pair of rollers mounted about said shaft and having an aggregate width exceeding that of the fabric, and means for effecting lateral adjustment of said rollers along said shaft each to and from a median position relative to the fabric width, the arrangement being such that if there is a backward bow in the fabric the rollers can be adjusted transversely thereof each away from the median position to leave a gap therebetween whereby the center of the fabric travels through a shorter path than the remainder thereof in movement through said return bend thus to remove the how.

The shaft may be stationary or rotatable, but in either case the rollers are rotatable.

The rollers may be adjusted lengthwise of the shaft by any suitable means such as a rightand left-hand threaded rod or shaft disposed parallel to and spaced from the roller-mounting shaft and rotatable to displace therealong towards and away from one another tapped tubes in threaded engagement with the opposite-handed threads of the shaft and carrying arms terminating in yokes straddling reduced diameter portions of said rollers adjacent the mutually remote ends of the latter.

An embodiment of the invention will now be described, by way of example, with reference to the accompanying drawing in which:

FIG. 1 is a front elevational view of a device for removing backward bow in the weft threads of woven fabrics or in courses of knitted fabrics;

FIG. 2 is a schematic sectional view taken on the line 2-2 of FIG. 1; and

FIGS. 3 and 4 are diagrammatic views indicating a web of fabric passing to and from the device in conditions respectively, where the fabric has no backward bow, and where it has a backward bow.

Webs of fabric may undergo various kinds of finishing treatments and in such treatments it is usual for a web of fabric to be progressed in the direction of its length between fabric take-off and fabric take-up mechanisms, driving means being provided for so progressing the fabric, which fabric take-off and fabric take-up mechanisms and driving means therefor may be of any preferred or conventional construction forming no part of the present invention and, hence, are not shown in the accompanying drawings.

Referring now to the drawing, the device for removing backward bow in the weft threads of woven fabrics or in courses of knitted fabrics is located in the path of 14 supported in a housing 15.

movement between the take-off and take-up mechanisms and so disposed relative to said mechanisms as to provide an outward path as indicated by arrow A from the takeoff mechanism, and a return path as indicated by arrow B to the take-up mechanism. The bow straightening device provided at the locus of the change in direction of fabric progressed between the take-off and take-up mechanisms comprises a transversely-disposed shaft 10 of substantially greater length than the maximum width of fabric to be treated and two rollers 11 and 12 of equal length mounted about said shaft and of aggregate length less than that of the shaft 10 but greater than the maximum width of fabric. The shaft 10 may be stationary and the rollers 11 and 12 adapted to rotate relative to the shaft, but in the embodiment shown the shaft is mounted at each of its ends to rotate freely in bearings 13 and The shaft 10 is formed with a longitudinal groove 'or keyway 16 extending over its entire length and each roller is formed along its inner periphery 17 with a longitudinal rib or key 18 extending over its entire length and which has a sliding fit in the keyway 16. Thus the rollers 11 and 12 rotate with the shaft 10 when the latter rotates in its end bearings 13 and 14, and can slide lengthwise of the shaft towards and away from one another. The rollers are hemispherical at their inner or directly opposing ends 19, and at their outer or mutually remote ends 20 have bobbin-shaped extensions comprising a median reduced diameter portion 21 flanked by flanges 22. The ribs or keys 18 extend through the extensions. The web W in its progress contacts the roller peripheries and effects a return bend movement therearound, and in so doing rotates the rollers 11 and 12 and shaft 10.

Any suitable known means may be provided for transverse adjustment of the rollers 11 and 12 along the shaft 10 each to and from the median position where they abut or substantially abut one another as shown in FIG. 3. In the embodiment of the invention illustrated (see particularly FIG. 1) the means for effecting this transverse adjustment of the rollers comprises a shaft 23 mounted above and in spaced and parallel relation to the shaft 10 and rollers 11 and 12, the shaft 23 being externally screwthreaded for some distance from near each end towards the center thereof. The threads are of opposite hand, that at the left-hand of the shaft as seen in FIG. 1 being denoted 24 and being a left-hand thread and that at the right-hand of the shaft as seen in FIG. 1 being denoted 25 and being a right-hand thread. Theshaft 23 is supported at its ends in bearings 26 and 27 and is freely rotatable, a hand-wheel 28 being secured on one end of the shaft for control of such rotation.

Mounted about each threaded portion of the shaft 23 and in screw-threaded engagement with the thread thereat is a short tapped tube 29 from which depends an arm 30 fashioned at its lower end as a yoke 31 received between the fianges 22 and straddling the reduced diameter portion 21 between the flanges. It will be manifest that if the handwheel 28 is rotated in a clockwise direction the tubes 29 will move along the shaft 23 towards one another and the yokes 31 will simultaneously urge the rollers 11 and 12 from the positions shown in full lines in FIG. 1 towards the positions shown in chain-dotted lines in FIG. 1 to bring the hemispherical ends 19 of the rollers 11 and 12 into contact with one another and thus in effect to form the equivalent of a single roller. Likewise, counter-clockwise rotation of the hand-wheel 28 will move the rollers 11 and 12 away from one another leaving a gap therebetween.

In operation, if the weft threads of a web W of fabric have a backward bow, as indicated diagrammatically at 33a in FIG. 4, the rollers 11 and 12 are adjusted away from the median position along the shaft 10, thus to leave i 3 a gap therebetween whereby the web of the fabric in its returnbend movement'travels through a path'which becomes increasingly shorter as the longitudinal center line of the fabric is approached, the selvedges of the fabric travelling about the peripheries of the rollers and the web consequently being bowed in the transverse direction as it effects said return bend movement. As a result the backward bow is corrected and the weft threads or courses are straightened, as indicated diagrammatically at 33b in FIG. 4, when the web travels up to the direction-changing roller 32. When there is no bow, as indicated diagrammatically at 34 in FIG. 3, the rollers are adjusted back to the median position to place them close together and to provide in effect a single continuous roller.

Manifestly changes in details of construction can be effected without departing from the spirit and scope of the invention.

I claim:

1. A device for removing backward bow in the weft threads of woven fabrics or in courses of knitted fabrics being progressed in a lengthwise direction, comprising a shaft disposed transversely to the line of progress of the fabric to effect a return bend in said line of progress, a pair of rollers mounted on said shaft and having an aggregate Width exceeding that of the fabric, and means for efiecting lateral adjustment of said rollers along said shaft each to and from a median position relative to the fabric width, whereby if there is a backward bow in the fabric the rollers can be adjusted transversely thereof each away from the median position to leave a gap therebetween whereby the center of the fabric travels through a shorter path than the remainder thereof in movement through said return bend thus to remove the bow.

2. A device as claimed in claim 1, in which the rollers are freely rotatable.

3. A device as claimed in claim 1, in which the shaft is freely rotatable and the rollers are keyed to the shaft for rotation therewith.

4. A device as claimed in claim 1, wherein said means for effecting lateral adjustment of said rollers along said shaft comprises a rightand left-hand threaded rod disposed parallel to and spaced from the roller-mounting shaft, tapped tubes in threaded engagement with the opposite hand threads, said rod being rotatable to displace therealong towards and away from one another said tapped tubes, arms on said tubes terminating in yokes, said rollers having reduced diameter portions adjacent the mutually remote ends thereof, said yokes straddling said reduced diameter portions.

No references cited. 

